U.S. companies have sold more than $245 billion — or almost aquarter of all bonds issued this year — in only seven weeks. Andinvestors can't get enough, driving down borrowing costs for eventhe junk-rated issuers to 14-month lows.

“To borrow a phrase from a couple great singers in history, it'sfeeling a little bubblelicious in the credit markets,” Mike Swell,co-head of global portfolio management for fixed income at GoldmanSachs Asset Management, said in an interview on Bloomberg TV.

With the month not even half over, more than $30 billion inissuance this week has already cemented August as the busiest since2010 for debt sales by blue-chip companies, according to datacompiled by Bloomberg. The high-yield market is also showing signsof life, with junk-rated companies selling more than $11 billion ofnotes this month, compared with $14.5 billion in July.